12 research outputs found
Production of dust by massive stars at high redshift
The large amounts of dust detected in sub-millimeter galaxies and quasars at
high redshift pose a challenge to galaxy formation models and theories of
cosmic dust formation. At z > 6 only stars of relatively high mass (> 3 Msun)
are sufficiently short-lived to be potential stellar sources of dust. This
review is devoted to identifying and quantifying the most important stellar
channels of rapid dust formation. We ascertain the dust production efficiency
of stars in the mass range 3-40 Msun using both observed and theoretical dust
yields of evolved massive stars and supernovae (SNe) and provide analytical
expressions for the dust production efficiencies in various scenarios. We also
address the strong sensitivity of the total dust productivity to the initial
mass function. From simple considerations, we find that, in the early Universe,
high-mass (> 3 Msun) asymptotic giant branch stars can only be dominant dust
producers if SNe generate <~ 3 x 10^-3 Msun of dust whereas SNe prevail if they
are more efficient. We address the challenges in inferring dust masses and
star-formation rates from observations of high-redshift galaxies. We conclude
that significant SN dust production at high redshift is likely required to
reproduce current dust mass estimates, possibly coupled with rapid dust grain
growth in the interstellar medium.Comment: 72 pages, 9 figures, 5 tables; to be published in The Astronomy and
Astrophysics Revie
Stereoselective analysis of labetalol in human plasma by LC-MS/MS: Application to pharmacokinetics
Analysis of the expression of two genes of Dictyostelium discoideum which code for developmentally regulated cysteine proteinases
Structural analysis of a developmentally regulated sequence encoding for a cysteine proteinase in Dictyostelium discoideum
A historical argument for regulatory failure in the case of Primodos and other hormone pregnancy tests
High-performance liquid chromatographic determination of β-adrenoceptor blocking agents in body fluids
The relations between evolution and domestication reconsidered - Implications for systematics, ecology, and nature conservation
DarkSide-50 results and the future liquid argon dark matter program
DarkSide uses a dual-phase Liquid Argon Time Projection Chamber (TPC) to search for WIMP dark matter. The paper will present the latest result on the search for low mass (MW IMP < 20 Gev/c2) and high mass (MW IMP > 100 Gev/c2) WIMPs from the current experiment, DarkSide-50, running since mid 2015 a 50-kg-active-mass TPC, filled with argon from an underground source. The next stage of the DarkSide program will be a new generation experiment involving a global collaboration from all the current Argon based experiments. DarkSide-20k, is designed as a 20-tonne fiducial mass TPC with SiPM based photosensors, expected to be free of any background for an exposure of >100 ton x years. Like its predecessor DarkSide-20k will be housed at the Gran Sasso (LNGS) underground laboratory, and it is expected to attain a WIMP-nucleon cross section exclusion sensitivity of 10−47 cm2 for a WIMP mass of 1 TeV /c2 in a 5 yr run. A subsequent objective, towards the end of the next decade, will be the construction of the ultimate detector, ARGO, with a 300 t fiducial mass to push the sensitivity to the neutrino floor region for high mass WIMPs. The combination of the three experiments, part of a single family, will cover completely the WIMP hypothesis from 1 GeV /c2 to several hundreds of TeV /c2 masses